Local PV是从kuberntes 1.10开始引入，本质目的是为了解决hostPath的缺陷。通过PV控制器与Scheduler的结合，会对local PV做针对性的逻辑处理，从而，让Pod在多次调度时，能够调度到同一个Node上。
kubernetes v1.14.0正式发布了，这个版本带来的一个新特性就是本地持久化管理( Local StorageManagement)特性正式GA(稳定)了。

一，安装local-path-provisioner

1，当k3s正常安装完成之后，就已预安装好了local-path-provisioner。

NAME                                     READY   STATUS      RESTARTS   AGE
svclb-traefik-wwr4q                      2/2     Running     6          19h
svclb-traefik-tkzjl                      2/2     Running     4          8h
helm-install-traefik-zdsx4               0/1     Completed   0          33m
traefik-758cd5fc85-m8j5n                 1/1     Running     0          33m
coredns-7944c66d8d-bdk4f                 1/1     Running     2          8h
local-path-provisioner-6d59f47c7-l2zc9   1/1     Running     3          8h
metrics-server-7566d596c8-csdqb          1/1     Running     3          8h

倒数第二个就是：local-path-provisioner-6d59f47c7-l2zc9。
2，local-storage的配置
/var/lib/rancher/k3s/server/manifests/local-storage.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: local-path-provisioner-service-account
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: local-path-provisioner-role
rules:
- apiGroups: [""]
  resources: ["nodes", "persistentvolumeclaims"]
  verbs: ["get", "list", "watch"]
- apiGroups: [""]
  resources: ["endpoints", "persistentvolumes", "pods"]
  verbs: ["*"]
- apiGroups: [""]
  resources: ["events"]
  verbs: ["create", "patch"]
- apiGroups: ["storage.k8s.io"]
  resources: ["storageclasses"]
  verbs: ["get", "list", "watch"]
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: local-path-provisioner-bind
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: local-path-provisioner-role
subjects:
- kind: ServiceAccount
  name: local-path-provisioner-service-account
  namespace: kube-system
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: local-path-provisioner
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: local-path-provisioner
  template:
    metadata:
      labels:
        app: local-path-provisioner
    spec:
      serviceAccountName: local-path-provisioner-service-account
      tolerations:
          - key: "CriticalAddonsOnly"
            operator: "Exists"
          - key: "node-role.kubernetes.io/master"
            operator: "Exists"
            effect: "NoSchedule"
      containers:
      - name: local-path-provisioner
        image: rancher/local-path-provisioner:v0.0.11
        imagePullPolicy: IfNotPresent
        command:
        - local-path-provisioner
        - start
        - --config
        - /etc/config/config.json
        volumeMounts:
        - name: config-volume
          mountPath: /etc/config/
        env:
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
      volumes:
        - name: config-volume
          configMap:
            name: local-path-config
---
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: local-path
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
provisioner: rancher.io/local-path
volumeBindingMode: WaitForFirstConsumer
reclaimPolicy: Delete
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: local-path-config
  namespace: kube-system
data:
  config.json: |-
        {
                "nodePathMap":[
                {
                        "node":"DEFAULT_PATH_FOR_NON_LISTED_NODES",
                        "paths":["/var/lib/rancher/k3s/storage"]
                }
                ]
        }

/var/lib/rancher/k3s/storage为节点存储空间
3，确认storageclass资源已生成

[root@localhost yaml]# kubectl get storageclass -n kube-system
NAME                   PROVISIONER             RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
local-path (default)   rancher.io/local-path   Delete          WaitForFirstConsumer   false                  20h

二，创建PVC

1，pvc.yaml内容如下:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: local-path-pvc
  namespace: default
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: local-path
  resources:
    requests:
      storage: 50Mi

2，将Yaml文件应用到k3s集群
kubectl apply -f pvc.yaml
3，查看pv

kubectl get pv -A
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                    STORAGECLASS   REASON   AGE
pvc-1d6d8a75-93cd-4f89-bef7-2251ce1695bd   50Mi       RWO            Delete           Bound    default/local-path-pvc   local-path              25m

4，查看pvc

kubectl get pvc -A
NAMESPACE   NAME             STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
default     local-path-pvc   Bound    pvc-1d6d8a75-93cd-4f89-bef7-2251ce1695bd   50Mi       RWO            local-path     27m

三，创建测试POD

1，pvc-pod.yaml内容如下：

apiVersion: v1
kind: Pod
metadata:
  name: volume-test
  namespace: default
spec:
  containers:
  - name: volume-test
    image: nginx:1.18-alpine
    imagePullPolicy: IfNotPresent
    volumeMounts:
    - name: volv
      mountPath: /data
    ports:
    - containerPort: 80
  volumes:
  - name: volv
    persistentVolumeClaim:
      claimName: local-path-pvc

2，将Yaml文件应用到k3s集群
kubectl apply -f pvc-pod.yaml
3，查看pod的部署节点

kubectl get pod -o wide
NAME                                READY   STATUS    RESTARTS   AGE     IP           NODE                    NOMINATED NODE   READINESS GATES
nginx-deployment-559fdddb7b-cb8xz   1/1     Running   2          7h39m   10.42.2.19   localhost.localdomain   <none>           <none>
nginx-deployment-559fdddb7b-qw6pn   1/1     Running   2          7h39m   10.42.1.23   k3s-agent.localdomain   <none>           <none>
volume-test                         1/1     Running   0          34s     10.42.1.27   k3s-agent.localdomain   <none>           <none>

4，查看k3s-agent.localdomain 节点目录

 ll /var/lib/rancher/k3s/
total 4
drwx------. 3 root root 4096 Oct 24 21:46 agent
drwxr-xr-x. 3 root root   78 Oct 24 21:46 data
drwxr-xr-x. 3 root root   54 Oct 25 17:10 storage

可以看到，在local-storage.yaml定义的目录已生成。

四，验证

1，在pod中写入文件

/data # echo "hello, local PV" > pvc-test
/data # cat pvc-test 
hello, local PV
/data # pwd
/data

2，在local PV查看是否同样有此文件

pwd
/var/lib/rancher/k3s/storage/pvc-1d6d8a75-93cd-4f89-bef7-2251ce1695bd
[root@k3s-agent pvc-1d6d8a75-93cd-4f89-bef7-2251ce1695bd]# ls
pvc-test
[root@k3s-agent pvc-1d6d8a75-93cd-4f89-bef7-2251ce1695bd]# cat pvc-test 
hello, local PV